1) Field of the Invention
The present document describes lenses for variable focus which provide variable focus, including technical lenses for variable focus for, for example, cameras and medical lenses for variable focus, for, for example, outside the eye, spectacles, or for inside the eye, as intraocular lenses, henceforth: “IOLs”, in particular accommodating intraocular lenses, henceforth: “AIOLs”. The lenses for variable focus disclosed in the present document can be optical components of said cameras, of spectacles and of intraocular lenses with application of said lenses not restricted thereto. Optical and mechanical principles of such lenses for variable focus are similar for the technical and the medical applications of such lenses. For illustration and explanation the IOLs and AIOLs will be used henceforth to set forth the optical and mechanical principles of these lenses for variable focus.
2) Discussion of the Prior Art
IOLs replace the natural lens of the eye when the natural lens is removed during cataract surgery, as an aphakic lens, or used in the eye as an addition to the natural lens, as a phakic lens. Intraocular lenses are generally monofocal and offer sharp vision at one distance only. AIOLs provide sharp vision over a range of distances, from, for example, reading distance up to infinity by variable focus and AIOLs are generally driven by contraction and relaxation of muscles of the human eye which also drives the natural process of accommodation. Principles for AIOLs include lateral and axial movement of optical elements, as set forth in, for example, S. Masket, Cataract and refractive surgery today, July 2004, pp. 34-37. Axial movement, in the context of the present document, means movement along the optical axis of the lens.